Eight people ― four men, four women ― locked in a paradise under glass for two years. No one and nothing is allowed in or out. The world is watching.

In 2016, this sounds like the setup for a no-holds-barred reality show. But in the early 1990s, Biosphere 2 was a real and at least somewhat scientific venture. Built by an idealistic team including inventor John Allen and billionaire backer Ed Bass, the glassed-in enclosure held five biomes, allowing eight adults to subsist on the agricultural output and oxygen within. The concept: to create a totally self-sufficient, enclosed biosphere in which humans could survive without external intervention for two years. (Next stop: colonies on Mars!)

In reality, the project fell short of its lofty goals. Just 12 days into the experiment, one crew member had to leave for several hours for emergency medical treatment beyond the capacity of the team’s lone doctor. By the second year, oxygen and other supplies were being sent in with relative frequency. A second team sent in for another two-year mission only lasted a few months before the whole organization dissolved.